Blasting device for cleaning relatively large surfaces

ABSTRACT

A blasting device in which a base post of a telescopic boom composed of a multiplicity of posts is pivotably mounted at the lower end thereof on a turntable provided on a vehicle, such as a truck, a swingable frame adapted to swing freely to desired positions is arranged at the end of an uppermost post of said multiplicity of posts, a vertically movable frame engages said swingable frame, and a blasting means is attached to the front end of an expansion frame provided on said vertically movable frame.

United States Patent Watanabe et a1.

1 Sept. 30, 1975 BLASTING DEVICE FOR CLEANING RELATIVELY LARGE SURFACES Inventors: Susumu Watanabe, Nagoya; Hiromu Sato; Toyoji Fuma, both of Toyokawa; Hitoshi Takeda, Toyohashi, all of Japan Assignee: Sintokogio, Ltd., Japan Filed: July 5, 1974 Appl. No.: 485,882

[30] Foreign Application Priority Data July 12, 1973 Japan 48-78606 US. Cl 51/9 M; 51/9 M Int. Cl. B24C 3/06 Field of Search 51/9 M, 9 R, 8 R; 114/222,

[56] References Cited U NITED STATES PATENTS 3.262.228 7/1966 Schenck 51/9 M 3.548.541 12/1970 Miller 51/9 M X 3,566,543 3/1971 Fogle i v 51/9 M 3,747,277 7/1973 Carpenter i 51/9 M .788010 1/1974 Goff 51/9 M 3827.187 8/1974 Yamamotol 51/9 M X Primary E\aminerDonald G. Kelly I Attorney, Agent, or FirmArmstrong, Nikaido & Wegner [57 ABSTRACT 16 Claims, 10 Drawing Figures Sheet 1 of 9 Sept. 30,1975

U.S. Patent US. Patent Sept. 30,1975 Sheet 2 of 9 3,908,314

'U.S. Patent Sept. 30,1975 Sheet 3 of9 3,908,314

MGQ

US. Patent Sept. 30,1975 Sheet4of9 3,908,314

Sheet 5 of 9 U.S. Patent Sept. 30,1975

US. Patent Sept. 30,1975 Sheet 6 of9 3,908,314

U.S. Patent Sept. 30,1975 Sheet 8 of9 3,908,314

US. Patent Sept. 30,1975 Sheet 9 of-9 3,908,314

BLASTING DEVICE FOR CLEANING RELATIVELY LARGE SURFACES The present invention relates to a blasting device adapted to clean surfaces, particularly side surfaces, of large structures, such as ship shells, panels of gas tanks, and wainscotting of buildings.

Heretofore, in accordance with the prior art, when cleaning such surfaces of large structures as described above, there has been commonly used a so-called packaged blasting unit which cleans the surfaces while being moved vertically along the surfaces. This packaged blasting unit includes as integral parts thereof a projecting means to project an abrasive material, an abrasive material supplying means for the abrasive material supplied to said projecting means, an abrasive material reclaiming and cycling means for attaining the reuse of the projected abrasive material, and a separator for separating the dust produced during a cleaning operation from the abrasive material. In addition to this packaged blasting unit, there has been used a blasting device in which rugged guide frames are provided to move vertically a packaged blasting unit, and said guide frames are movable along rails and the like so that a cleaning operation is performed.

In these conventional blasting devices, however, a provision must be made to maintain a projecting opening of the packaged blasting unit in tight contact with the surface continuously during a cleaning operation for eliminating a possibility that the projected abrasive material will fly out of the blasting device during the cleaning operation. To achieve this purpose, the prior art has employed a technique in which a suitable number of magnets are arranged in the packaged blasting unit so that the projecting opening of the packaged blasting unit is brought into tight contact with the surface, and a technique in which the packaged blasting unit is inclined with respect to the vertical utilizing the weight of the unit so that the projecting opening of the unit is forcedly brought into tight contact with the surface. However, in the former technique, in order to overcome the difficulty in movement of the packaged blasting unit it is necessary to deenergize the magnets each time the unit is to be moved or to provide a separate hydraulic cylinder by the operation of which the packaged blasting unit is forcedly separated from the surface. Further, in the latter technique, it is often rendered impossible to bring the packaged blasting unit satisfactorily into tight contact with the surface depending upon the angle of inclination of the surface, resulting in various disadvantages such as flying-out of abrasive material, incorrect projection, and the like. Furthermore, the aforesaid abrasive material reclaiming and cycling means attached to the packaged blasting unit is inevitably located outside the projecting means due to the essential feature of the construction thereof, with the result that the packaged blasting unit becomes not only very bulky but also unstable in construction. Needless to say, such a construction is not suitable for the packaged blasting unit which operates at places high above the ground. This constitutes another great disadvantage.

The present invention has been completed to preclude such disadvantages of the conventional blasting devices as described above.

The present invention relates to a blasting device in which a swingable frame is provided at the top end of a telescopic boom disposed on a vehicle, an expansion frame adapted to expand toward and contract away from the surface is attached to a vertically movable frame which is arranged on said swingable frame and moves vertically along said swingable frame, and a packaged blasting unit is attached to said expansion frame so that sealing members of said packaged blasting unit are surely brought into tight contact with the surface, a projected abrasive material is reclaimed in a very sure manner, the dust produced during a cleaning operation is separated correctly from the abrasive material, the vibrations caused by high-speed rotation of the parts in the packaged blasting unit are effectively absorbed, and the packaged blasting unit is constructed compact and light weight.

These objects and features of the present invention will become more clear by the following description of a preferred embodiment taking reference with the attached drawings showing the preferred embodiment of the present invention, in which:

FIG. 1 is a partly broken away side view illustrating the blasting device in accordance with the present invention with a boom thereof extended upright;

FIG. 2 is a partly broken away side view showing the blasting device in accordance with the present inven tion which is cleaning an inclined surface;

FIG. 3 is a partly broken away side view illustrating the blasting device in accordance with the present invention with the boom being contracted, swung down, and placed in a storage position;

FIG. 4 is a partly broken away front view showing a packaged blasting unit of the blasting device in accordance with the present invention;

FIG. 5 is a partly broken away side view illustrating the packaged blasting unit;

FIG. 6 is a partly broken away side view showing an impeller unit of the blasting device in accordance with the present invention;

FIG. 7 is an enlarged view illustrating the important part of FIG. 6;

FIG. 8 is a view seen in the direction of the line VIII- VIII of FIG. 4;

FIG. 9 is a view seen in the direction of the line IXIX of FIG. 4; and

FIG. 10 is a view seen in the direction of the X-X of FIG. 1.

I-Iereunder the present invention will be explained in detail with reference to the embodiment thereof shown in the attached drawings.

A vehicle 1 on which the whole blasting device is mounted, is an endless track crawler type vehicle having tracks 2, which is moved by a prime mover (not shown). The vehicle 1 has thereon a turntable 4 which in turn has thereon a rotating panel 5. An operating room 3 is located on the rotating panel 5. The turntable 4 can be rotated by operating a control means (not shown) provided in the operating room 3. Bearings 6 are securely fixed on the rotating panel 5, and the lower end of a base post 8 of a boom 7 is swingably pivoted on a pivot 9 supported by said bearings 6. The boom 7 is composed of the base post 8, a section post 10 fitted into the base post 8, a section post 11 fitted into said section post 10, and a section post 12 fitted into said section post 11, thus forming a multiply fitted posts construction. These section posts 10 through 12 are telescopically mounted on each other, thus are freely extended or contracted one after another with the use of the hydraulic pressure provided by a pump (not shown), so that the boom 7 can attain all desired lengths. On the rotating panel is supported a pivot 14 on which the base of a hydraulic cylinder 13 is pivotally mounted. The end of a piston rod 15 of said hydraulic cylinder 13 is pivoted on a pivot 16 provided on the outer surface of the base post 8 of the boom 7 at a position midway between the both ends of said base post 8. Brackets 17 are fixed securely to the end of the uppermost section post 12 of the boom 7. A swingable frame 18 is pivoted at a position midway between the both ends thereof on a pivot 19 disposed at the upper ends of said brackets 17. The base ofa hydraulic cylinder 20 is rotatably pivoted on a pivot 21 arranged at the lower ends of the brackets 17. The end of a piston rod 22 of said hydraulic cylinder 20 is pivoted on a pivot 23 provided on said swingable frame 18, so that the swingable frame 18 can swing to any desired position. As shown in FIG. 10, inside the swingable frame 18 there is slidably arranged a vertically movable frame 24 having a plurality of rollers 25 which are guided and roll along the inner surfaces of said swingable frame 18. One end of each rope 26 is attached to respective hooks 24a in the lower portion of the vertically movable frame 24. Each rope 26 is trained about respective pulleys 27 at the upper end of the swingable frame 18, and extends downwardly to be trained about respective pulleys provided at the end of a piston rod 29 of a hydraulic cylinder 28 attached to the lower portion of the swingable frame 18. Each rope 26 further extends upwardly to be fixed in respective rope holes 18a arranged in respective brackets on the swingable frame 18. When the piston rod 29 retracts into the hydraulic cylinder 28, the vertically movable frame 24 is moved upwardly along the swingable frame 18 by virtue of the operation of the ropes 26. On the other hand, when the piston rod 29 is extended outwardly of the hydraulic cylinder 28, the ropes 26 are loosened and the vertically movable frame 24 moves downwardly due to the weight thereof along the swingable frame 18. In front of the vertically movable frame 24 there is disposed a pantagraph-type expansion frame 31 which is movable toward and away from the vertically movable frame 24 by means of a hydraulic cylinder (not shown). Brackets 33 are securely fixed on the two vertical sides of a fitting plate 32 provided at the front end of said expansion frame 31. At the ends of the brackets 33 there are pivotally supported pivots 35 mounted on a supporting frame of a packaged blasting unit 34 which will be described in detail hereinafter.

The construction of the packaged blasting unit 34 will be explained with reference to FIGS. 4 through 9. The packaged blasting unit 34 comprises an impeller unit 36, a rotary bucket-conveyor 37 for supplying an abrasive material to said impeller unit 36 and for reclaiming the abrasive material which finished a cleaning operation, a bucket casing 38 surrounding the rotary bucket-conveyor 37, a blasting chamber 39, and the supporting frame 40 for supporting the parts described above. Said blasting chamber 39 is securely fixed to a partition plate 41 having an opening 41a. A supporting plate 42 with an opening 42a is securely fixed above the partition plate 41. The supporting plate 42 extends downwardly to connect to the lower portion of the bucket casing 38, with a suitable space 42b being formed between the supporting plate 42 and the partition plate 41. The impeller unit 36 is disposed on a base 43 attached to said supporting plate 42. Referring to FIGS. 6 and 7, thetimpeller unit 36 includes a driving motor 46 having a motor shaft 45 to which rotary blades 44 are directly connected. The driving motor 46 and a cover 47 for said rotary blades 44 are mounted on the common base 43. A fitting portion 48 of the driving motor 46 is attached to said base 43 by means of bolts 50 through pairs of rubber tubes 49 for absorbing vibrations, each of the rubber tubes 49 having flange portions 49a. The base 43 is mounted on a rubber sheet 51 lined on the supporting plate 42 attached to the blasting chamber 39. The numeral 52 indicates a washer placed between the neck of the bolt 50 and the rubber tube 49. The numeral 53 designates a tube seat fitted on the outer peripheral surface of the bolt 50. The tube seats 53 are used for positioning the driving motor 46. To the end of the motor shaft 45 is directly attached an abrasive material distributing means 54 by means of bolts and nuts (not shown). The inner surfaces of the cover 47 are lined with wear-resistant protecting plates 55. The ends of said protecting plates 55 project into the blasting chamber 39 through an opening 56 of the base 43 and an opening 42a of the supporting plate 42. The numerals 57 and 58 indicate respectively a cage for maintaining a correct direction of projection of abrasive material and a labyrinth seal portion. The numeral 59 designates a disc which is fitted onto the motor shaft 45 for rotating therewith and cooperates with the labyrinth seal portion 58 to eliminate a possibility that the abrasive material will fly out the regular path thereof and hits on the bearing portion of the driving motor 46 damaging the bearing portion.

Hereunder an explanation will be made on the rotary bucket conveyor 37 and the bucket casing 38. The rotary bucket-conveyor 37 is provided inside the bucket casing 38 attached to the outer peripheral portion of the partition plate 41. As shown in FIG. 8, the rotary bucket-conveyor 37 comprises two doughnut-shaped side discs 63 and an outer plate 64 covering the outer peripheries of said side discs 63. A plurality of pairs of receiving rollers 60 support the both edge portions of the outer plate 64. Said pairs of receiving rollers 60 are securely fixed to shafts 62a rotatably supported by bearings 62 bearing covers 61 attached to said bucket casing 38. The rotary bucket-conveyor 37 surrounds the impeller unit 36, and gear teeth are provided at the central portion of and throughout the whole periphery of the outer plate 64 of the rotary bucket-conveyor 37. The gear teeth 65 are in engagement with a pinion 67 securely fixed to a shaft of a reduced motor 66 attached to one vertical surface of the bucket casing 38, so that the rotary bucket-conveyor 37 can be rotated. In order to form buckets 68, a plurality of partition plates are arranged at given intervals between the side discs 63 of said rotary bucket-conveyor 37. One or two rib-like weirs 68a are provided inside each bucket 68. The weirs 68a are employed for the purpose of minimizing the amount of abrasive material which falls from the buckets 68 when the whole packaged blasting unit 34 including the rotary bucket-conveyor 37 is inclined with respect to the vertical as is the case when cleaning an inclined surface. A chute 69 is disposed at the inner upper portion of the bucket casing 38, and the end of said chute 69 opens into an abrasive material introducing pipe 70 of the impeller unit 36. A dust collecting duct 71 is connected to the upper portion of the bucket casing 38. The duct 71 is adapted to discharge the dust existing in the bucket casing 38 and the blasting chamber 39 through an opening 72. The lower end of the bucket casing 38 forms a U-shaped abrasive material storage 73. The abrasive material in the abrasive material storage 73 is scooped up by the buckets 68. The opening 72 plays a role that, when an excessive amount of abrasive material falls from the rotary bucket conveyor 37 into the chute 69 and is stored therein, a part of the stored abrasive material is discharged through the opening 72 and the space 42b to reach the abrasive material storage 73.

I-Iereunder an explanation will be given on the blasting chamber 39 and the supporting frame 40. The blasting chamber 39 attached to the partition plate 41 has an opening 95 facing the surface to be cleaned. Double sealing members 74 consisting of such a material as rubber are arranged on the peripheral edge of said opening 95. The lower portion of the blasting chamber 39 is formed by an inclined plate 75 the lower end of which connects to the abrasive material storage 73. The projected abrasive material slides down on the inclined plate 75 and freely falls into the abrasive material storage 73 through the space 42b between the partition plate 41 and the supporting plate 42. The whole packaged blasting unit 34 is rotatably supported at the upper and lower portions thereof by the supporting frame 40 composed of pipes. Atthe upper and lower portions of the supporting frame 40 there are provided bearings 77 in which are supported shafts 78 attached to the blasting chamber 39. Thus, the packaged blasting unit 34 is supported such that it can rotate about an axis extending between the upper and lower shafts 78. Since the pivots 35 disposed on the supporting frame 40 of the packaged blasting unit 34 are pivoted on the ends of the brackets 33 as described previously, the packaged blasting unit 34 can rotate in a vertical plane together with the supporting frame 40. The blasting chamber 39 is provided with four universal wheels 76 which travel on the surface. In the vicinity of said universal wheels 76 there is arranged an access switch 79 for confirming that the packaged blasting unit 34 is correctly in contact with the surface. The projecting opening is surrounded by a pipe 80 having air discharge nozzles. One end of a supporting bar 40a for the packaged blasting unit 34 is pivoted at 40b on the supporting frame 40. The other end of the supporting bar 40a is so constructed that said other end can be pinned in a seat 40c disposed on the fitting plate 32 of the expansion frame 31. With this construction, when the boom 7 is swung, inclination of the packaged blasting unit 34 due to the weight thereof can be prevented by pinning the other end of the supporting bar 40a into the seat 400 on the supporting plate 32 of the expansion frame 31. And when a cleaning operation is to be started, the supporting bar 40a can be folded along the supporting frame 40. In the packaged blasting unit 34 with the above construction, the dust collecting duct 71 disposed in the bucket casing 38 is connected to multiply fitted ducts 83 extending through guides 82 provided respectively on the base post 8 and the section posts through 12 of the boom 7, through a connecting duct 81 disposed on the swingable frame 18 and through a casing 81a which slides on the connecting duct 81. A plurality of protecting bars 84 are arranged around the guides 82 at the both ends of the base post 8. An auxiliary vehicle 86 is connected to the vehicle 1 through a coupler 85 in such a manner that the auxiliary vehicle 86 can take any axial direction in relation to the vehicle 1. On said auxiliary vehicle 86 is loaded a dust collecting means 87 connected to a flexible duct 83a connected in turn to the end of the base duct of said multiply fltted ducts 83. A dust discharging screw conveyor 88 provided beneath said dust collecting means 87 has at the end thereof a rotary valve 89, so that the dust is discharged into a dust container 90 in a suitable manner. On said vehicle 86 there are loaded a control board 91, a generator 92, a fuel tank 93, and other equipments necessary for cleaning operation such as a pressure oil supply means for the boom and various auxiliary means including the hydraulic cylinders 13, 20, and 28. The numeral 94 in the figure indicates a take-up drum for winding electrical wires and compressed air supply hoses which is supported on a shaft disposed on the side of the base post 8 of the boom 7. Although the embodiment shown in the drawings employs three section posts 10 through 12, the number of these section posts may be suitably increased or decreased according to the conditions attending the use.

Hereunder an explanation will be given on the operation of the blasting device in accordance with the present invention which has the construction described above. First, the vehicle 1 with the boom 7 is brought near the surface to be cleaned as shown in FIG. 1, and the boom 7 is extended upwardly by thrusting out the section posts 10 through 12 one after another from the base post 8, so that the packaged blasting unit 34 is located in the vicinity of the uppermost portion of the surface. The extending operation of the boom 7 is terminated when the boom 7 has reached a desired height. Then, the pantagraph-type expansion frame 31 is operated by a hydraulic cylinder (not shown), so that the packaged blasting unit 34 is advanced and the universal wheels 76 come into tight contact with the surface. At this point, whether or not the sealing members 74 are correctly in tight contact with the surface, can be detected by the use of the access switch 79. If the surface to be cleaned is inclined, the hydraulic cylinder 20 is operated to incline the swingable frame 18 with respect to the vertical, so that, as shown in FIG. 2, the packaged blasting unit 34 is placed parallel to the inclined surface. With this operation, the sealing members 74 come uniformly into tight contact with the surface, and the flying-out of an abrasive material is prevented surely. The vertically movable frame 24 on which the packaged blasting unit 34 is mounted, is placed at the upper portion of the swingable frame 18 by operating the hydraulic cylinder 28 so that the ropes 26 are drawn. After the packaged blasting unit 34 has come correctly into tight contact with the surface, the driving motor 46 for the impeller unit is energized to rotate the rotary blades 44. At the same time, the rotary bucket conveyor 37 in the packaged blasting unit 34 is driven by the reduced motor 66, and the dust collecting means 87 on the auxiliary vehicle 86 is operated. In this way, the abrasive material is projected onto the surface to start a cleaning operation. The abrasive material projected onto the surface springs back from the surface and slides down on the inclined plate into the abrasive material storage 73. The abrasive material stored in the abrasive material storage 73 is scooped up by the buckets 68 of the rotary bucket conveyor 37 and is transported upwardly. Upon reaching the uppermost portion of the rotary bucket conveyor 37, the abrasive material falls continuously into the chute 69 forming layers. At this point, due to a suction air flow flowing from an air inlet (not shown) to the duct 71 across the falling layers of the abrasive material, relatively light particles and dust included in the abrasive material are carried away from the abrasive material layers. At the same time, an air flow is produced which flows from the blasting chamber through the opening 72 to the duct 71. Owing to this air flow, the dust containing air in the blasting chamber and the bucket casing 38 is sucked into the dust collecting means 87 through the duct 71, the connecting duct 81, the multiply fitted ducts 83, and the flexible duct 83a. In this way, the dust included in the abrasive material is separated from the abrasive material to be trapped in the dust collecting means 87, so that the abrasive material alone is supplied to the converged portion of the rotary blades 44 through the chute 69 and the abrasive material introducing pipe 70. The abrasive material supplied to the converged portion of the rotary blades 44 changes its direction of movement at the abrasive material distributing means 54 and moves toward the rotary blades 44 through an opening of the cage 57. The abrasive material which reached the rotary blades 44 is accelerated and projected onto the surface. The abrasive material thus projected cleans the surface, and then is reclaimed without flying out of the blasting device due to the tightly sealed state established by the double sealing members 74. The reclaimed abrasive material falls on the inclined plate 75 to slide down thereon and enters the abrasive material storage 73. When an inclined surface is cleaned, it often happens that the packaged blasting unit 34 inclines to an angle which is more than the resting angle at which the abrasive material begins to slide and fall, and the rotary bucket conveyor 37 is rotated in this inclined position. Even in such a case, the abrasive material which is scooped up by the bucket 68 and moves upwardly, is prevented from falling by two end edges, i.e., the end edge of one of the side discs 63 and the end edge of the weir 68a. Thus, the amount of abrasive material falling from the bucket 68 can be limited to a minimum, with the result that the amount of abrasive material supplied to the impeller unit is substantially the same as when the packaged blasting unit 34 is not inclined. This naturally leads to a cleaning operation which is performed uniformly at all times. By repeating the operational steps described above, the surface can be continuously cleaned, with the sealing members 74 around the projecting opening being moved slidingly. During the cleaning operation, vibrations due to a high-speed rotation of the rotary blades 44 and other causes can be effectively absorbed. Since the driving motor 46 is attached to the base 43 through the rubber tubes 49, the rubber tubes 49 absorb vibrations in vertical and horizontal directions which are produced by the driving motor 46, and only very small amounts of the vibrations are transmitted to the base 43. The vibrations in the axial direction of the bolts 60 are absorbed by the flange portions 49a of the rubber tubes 49. And the vibrations in the direction at right angles to said axial direction are absorbed by the body portions of the rubber tubes 49. Minor amounts of the vibrations transmitted to the base 43 are further absorbed by the rubber sheet 51 adjacent to the base 43, without being directly transmitted to the supporting plate 42. Thus, the vibrations transmitted to the packaged blasting unit 34 can be minimized very effectively. The boom 7 extended by thrusting out the section posts 10 through 12 one after another from the base post 8, is shortened by retracting by degrees the section posts 10 through 12 with the use of a hydraulic pump (not shown), so that the packaged blasting unit 34 moves downwardly slowly, cleaning the surface from the upper portion thereof to the lower portion thereof. When the boom 7 has been shortened to the limit by retracting to their respective limits the section posts 10 through 12 which were thrusted out one after another, the hydraulic cylinder 28 is operated to extend the piston rod 29 thereof so that the ropes 26 are loosened and the vertically movable frame 24 is moved down-' wardly. With this operation, the surface can be cleaned to the lowest portion thereof in a very sure manner. The ends of the ropes 26 are attached to the hooks 24a on the vertically movable frame 24 and fixed in the respective rope holes 18a in the upper respective brackets of the swingable frame 18, and the respective pulleys 30 which are attached to the piston rod 29. Thanks to this arrangement, the vertically movable frame 24 can be moved vertically through a distance twice the stroke of the piston rod 29. When the cleaning operation has reached a conclusion, the vehicle 1 is moved parallel to the surface by a distance equal to the projection width of the packaged blasting unit 34, and the packaged blasting unit 34 is brought into tight contact with the lowermost portion of the surface in contrast to the cleaning operation just completed. Then, the packaged blasting unit 34 is operated, and the section posts 10 through 12 are thrusted out one after another from the base post 8 to extend the boom 7, so that the packaged blasting unit 34 moves slowly upwardly from the lowermost portion of the surface for cleaning the whole area of a second work zone adjacent to a first work zone which has been just cleaned. In this manner, vertical movement of the packaged blasting unit 34 is repeated to complete the cleaning operation of all the area of the surface. In case the vehicle 1 cannot come near the surface a, the hydraulic cylinder 13 is operated to retract the piston rod 15, so that the boom 7 is swung and the packaged blasting unit 34 is brought in the vicinity of the surface, as shown in FIG. 2. Thereafter, the hydraulic cylinder 20 is operated for maintaining the packaged blasting unit 34 parallel to the surface with the result that the sealing members are brought into tight contact with the surface in a suitable manner and a cleaning operation is started. The above explanation applies to the case where the packaged blasting unit 34 is placed in tight contact with the surface and is moved vertically. In addition to this method of operation, the packaged blasting unit 34 can also be used in the following manner. That is, after the packaged blasting unit 34 has been placed in tight contact with the surface, the vehicle 1 is moved parallel to the surface to perform a cleaning operation. When the cleaning operation has been completed, the pantagraph-type expansion frame 21 is retracted, and the thrusted out section posts 10 through 12 are retracted one after another into the base post 8 for shortening the boom 7. Then, the hydraulic cylinder 28 is operated to extend the piston rod 29, so that the ropes 26 are loosened and t the vertically movable frame 24 is moved downwardly to a predetermined position. Subsequently, the hydraulic cylinder 28 is operated to swing downthe shortened boom 7, as shown in FIG. 3. All the above operations are performed by manipulating an operating means (not shown) provided in the operating room 3 on the turntable 4 of the vehicle 1. Although in this embodimerit of the present invention the pantagraph-type expansion frame 31 is used as a means for moving the packaged blasting unit 34 toward and away from the work surface, there may be alternatively employed some other construction such as the one in which horizontal guide rails project toward the surface to be cleaned from the front surface of the vertically movable frame 24, and the packaged blasting unit 34 engages said horizontal guide rails to be moved by a hydraulic cylinder toward and away from the surface. This embodiment of the present invention includes the pipe 80 with air discharge nozzles which is arranged around the packaged blasting unit 34. When a cleaning operation has been completed, these air discharge nozzles on the pipe 80 can be used to blow off the dust on the surface which has been cleaned.

As is clear from the explanations in the foregoing, in accordance with the present invention, the boom can be telescopically moved and swung, the swingable frame at the top end of the boom can be swung in any desired manner, and the packaged blasting unit is moved toward and away from the surface to be cleaned by means of the expansion frame so that the packaged blasting unit can take any position and direction in relation to the surface and can be placed precisely parallel to the surface. As a result, the sealing members of the packaged blasting unit come uniformly in tight contact with the surface, and the abrasive material never flys out of the packaged blasting unit. The surface blasting device in accordance with the present invention does not use conventional types of abrasive material reclaiming means such as the one employing a bucket elevator combined with a screw conveyor and the one having a construction that a chain provided with discs moves in a pipe. Due to this feature, the surface blasting device in accordance with the present invention can be constructed compact in size and light in weight, and the abrasive material is reclaimed smoothly and surely without trouble. Furthermore, in the surface blasting device in accordance with the present invention, the operation of vehicle, the control of the telescopic operation of boom, the control of the vertical movement of vertically movable frame, and the control of the swinging operation of swingable frame, are ingeniously combined, so that the neatly compacted packaged blasting unit can be maintained in a well-balanced state and can move smoothly and speedily at places high above the ground to continuously and effectively clean large surfaces. After the completion of a cleaning operation, the vertically movable frame is lowered and the boom is shortened and swung down to reduce the size of the entire blasting device. Therefore, it is very easy and safe to move the whole blasting device, and a small garage is enough for housing the surface blasting device. Further, since the surface blasting device in accordance with the present invention employs a double vibration absorbing means consisting of the rubber sheet and the vibration absorbing rubber tubes in the portion where the driving motor is attached to the packaged blasting unit, there can be obtained various advantages such as the one that vibrations produced by the packaged blasting unit operating at high places and including parts rotating at a high speed can be decreased greatly, so that a cleaning operation is performed under stable and safe conditions. The surface blasting device in accordance with the present invention can clean vertical and inclined wall surfaces of large structures including ship shells. Particularly when an inclined wall surface is cleaned, the abrasive material is reclaimed uniformly and smoothly. Thus, the surface blasting device in accordance with the present invention is an outstanding device which brings about numerous distinguishing benefitsto the industry.

We claim:

1. A blasting device including a vehicle, telescopic boom and a packaged blasting unit having an opening which is brought into tight contact with the surface to be cleaned and adapted to project an abrasive material through said opening onto said surface, comprising a first frame means having guiding arms pivotably mounted on the top end of said telescopic boom provided swingably on said vehicle, a second frame means engaged with said guiding arms and adapted to move along said guiding arms, supporting means provided on said second frame means, and adapted to support said packaged blasting unit and to move said packaged blasting unit in a direction substantially perpendicular to said guiding arms, a first operating means for rotating said first frame means in relation to said boom, a second operating means for moving said second frame means along said guiding arms, and a third operating means adapted to move said supporting means and to bring the opening of said packaged blasting unit into tight contact with said surface.

2. A blasting device in accordance with claim 1 in which said second operating means comprises a driving means consisting of a cylinder and a piston provided on said first frame means, guiding wheels arranged at the ends of said guiding arms, and ropes or chains, each end of them attached to said second frame means, engaged with said driving means through said guiding wheels so that said second frame means is moved upwardly along said guiding arms by said driving means.

3. A blasting device in accordance with claim 1 in which said supporting means includes a first supporting member which rotatably supports said packaged blasting unit on a vertical axis extending substantially on the center of gravity of said packaged blasting unit and substantially parallel to said opening, and a second supporting member adapted to rotatably support said first supporting member on a horizontal axis extending substantially on the center of gravity of said packaged blasting unit and substantially parallel to said opening so that said packaged blasting unit is rotated about said two axes conforming with the inclination of the surface to be cleaned.

4. A blasting device in accordance with claim 1 in which said telescopic boom is disposed on a turntable provided on said vehicle, and the base end of said boom is adapted to be able to move relative to said vehicle.

5. A blasting device in accordance with claim 1 in which said supporting means includes two arms supported on a same pivot to form an X shape and is adapted to move said packaged blasting unit in a direction perpendicular to said guiding arms due to the rotation of said two arms.

6. A blasting device in accordance with claim 3 in which said first operating means is adapted to rotate said first frame means to a storage position in which said first frame means is substantially parallel to said boom, and said supporting means has a housing means for connecting said first and second supporting members together so that said first and second supporting members are prevented from rotating relative to each other.

7. A blasting device in accordance with claim 1 in which a duct means for sucking from said packaged blasting unit the dust produced during a cleaning operation and separated from the abrasive material in said packaged blasting unit is provided along said telescopic boom so that said duct means can be telescopically mounted.

8. A blasting device in accordance with claim 1 in which said packaged b asting unit has a rotary bucket means comprising a plurality of buckets arranged in a circle and used for reclaiming the abrasive material projected onto the surface to be cleaned to project the abrasive material again, and a driving means for rotating said rotary bucket means.

9. A blasting device in accordance with claim 1 in which said packaged blasting unit includes an electric motor as a driving source for projecting said abrasive material, and said electric motor is attached to said packaged blasting unit through a vibration absorbing means and is adapted to place said opening surely in tight contact with said surface.

10. A blasting device in accordance with claim 1 in which said packaged blasting unit has air nozzle means and is adapted to remove the dust on the surface to be cleaned.

11. A blasting device in accordance with claim 2 in which said second frame means is adapted to move downwardly by the weight thereof along said guiding arms in response to the operation of said driving means.

12. A blasting device in accordance with claim 2 in which said blasting device includes second guiding wheels at the end of said piston, said ropes or chains extend and are trained about said first guiding wheels at the ends of said guiding arms and said second guiding wheels to connect said second frame means and said first frame means together, and said second frame is adapted to move on said guiding arms at a speed twice the moving speed of said piston.

13. A blasting device in accordance with claim 7 in which said duct means comprises an outermost fixed duct, at least one expansion duct adapted to be inserted telescopically into said fixed duct, and a protecting means which is provided around said fixed duct for protecting said fixed duct.

14. A blasting device in accordance with claim 1 in which said first operating means is constituted by a piston and a cylinder interposed between said boom and said first frame means.

15. A blasting device in accordance with claim 1 in which said vehicle is an endless track crawler type vehicle.

16. A blasting device in accordance with claim 1 including an auxiliary vehicle means coupled to said vehicle, a generator provided on said auxiliary vehicle means and used for operating said packaged blasting unit, and a dust collecting means provided on said auxiliary vehicle means and used for collecting the dust produced by a cleaning operation. 

1. A blasting device including a vehicle, telescopic boom and a packaged blasting unit having an opening which is brought into tight contact with the surface to be cleaned and adapted to project an abrasive material through said opening onto said surface, comprising a first frame means having guiding arms pivotably mounted on the top end of said telescopic boom provided swingably on said vehicle, a second frame means engaged with said guiding arms and adapted to move along said guiding arms, supporting means provided on said second frame means, and adapted to support said packaged blasting unit and to move said packaged blasting unit in a direction substantially perpendicular to said guiding arms, a first operating means for rotating said first frame means in relation to said boom, a second operating means for moving said second frame means along said guiding arms, and a third operating means adapted to move said supporting means and to bring the opening of said packaged blasting unit into tight contact with said surface.
 2. A blasting device in accordance with claim 1 in which said second operating means comprises a driving means consisting of a cylinder and a piston provided on said first frame means, guiding wheels arranged at the ends of said guiding arms, and ropes or chains, each end of them attached to said second frame means, engaged with said driving means through said guiding wheels so that said second frame means is moved upwardly along said guiding arms by said driving means.
 3. A blasting device in accordance with claim 1 in which said supporting means includes a first supporting member which rotatably supports said packaged blasting unit on a vertical axis extending substantially on the center of gravity of said packaged blasting unit and substantially parallel to said opening, and a second supporting member adapted to rotatably support said first supporting member on a horizontal axis extending substantially on the center of gravity of said packaged blasting unit and substantially parallel to said opening so that said packaged blasting unit is rotated about said two axes conforming with the inclination of the surface to be cleaned.
 4. A blasting device in accordance with claim 1 in which said telescopic boom is disposed on a turntaBle provided on said vehicle, and the base end of said boom is adapted to be able to move relative to said vehicle.
 5. A blasting device in accordance with claim 1 in which said supporting means includes two arms supported on a same pivot to form an X shape and is adapted to move said packaged blasting unit in a direction perpendicular to said guiding arms due to the rotation of said two arms.
 6. A blasting device in accordance with claim 3 in which said first operating means is adapted to rotate said first frame means to a storage position in which said first frame means is substantially parallel to said boom, and said supporting means has a housing means for connecting said first and second supporting members together so that said first and second supporting members are prevented from rotating relative to each other.
 7. A blasting device in accordance with claim 1 in which a duct means for sucking from said packaged blasting unit the dust produced during a cleaning operation and separated from the abrasive material in said packaged blasting unit is provided along said telescopic boom so that said duct means can be telescopically mounted.
 8. A blasting device in accordance with claim 1 in which said packaged blasting unit has a rotary bucket means comprising a plurality of buckets arranged in a circle and used for reclaiming the abrasive material projected onto the surface to be cleaned to project the abrasive material again, and a driving means for rotating said rotary bucket means.
 9. A blasting device in accordance with claim 1 in which said packaged blasting unit includes an electric motor as a driving source for projecting said abrasive material, and said electric motor is attached to said packaged blasting unit through a vibration absorbing means and is adapted to place said opening surely in tight contact with said surface.
 10. A blasting device in accordance with claim 1 in which said packaged blasting unit has air nozzle means and is adapted to remove the dust on the surface to be cleaned.
 11. A blasting device in accordance with claim 2 in which said second frame means is adapted to move downwardly by the weight thereof along said guiding arms in response to the operation of said driving means.
 12. A blasting device in accordance with claim 2 in which said blasting device includes second guiding wheels at the end of said piston, said ropes or chains extend and are trained about said first guiding wheels at the ends of said guiding arms and said second guiding wheels to connect said second frame means and said first frame means together, and said second frame is adapted to move on said guiding arms at a speed twice the moving speed of said piston.
 13. A blasting device in accordance with claim 7 in which said duct means comprises an outermost fixed duct, at least one expansion duct adapted to be inserted telescopically into said fixed duct, and a protecting means which is provided around said fixed duct for protecting said fixed duct.
 14. A blasting device in accordance with claim 1 in which said first operating means is constituted by a piston and a cylinder interposed between said boom and said first frame means.
 15. A blasting device in accordance with claim 1 in which said vehicle is an endless track crawler type vehicle.
 16. A blasting device in accordance with claim 1 including an auxiliary vehicle means coupled to said vehicle, a generator provided on said auxiliary vehicle means and used for operating said packaged blasting unit, and a dust collecting means provided on said auxiliary vehicle means and used for collecting the dust produced by a cleaning operation. 